swamp horsetail vs water horsetail

swamp horsetail and water horsetail both are nouns.

Word	Noun	Adjective	Verb	Adverb
swamp horsetail	Yes	No	No	No
water horsetail	Yes	No	No	No

As nouns, swamp horsetail and water horsetail are synonyms defined as:

swamp horsetail and water horsetail: Eurasia; northern North America to Virginia

Other synonyms of swamp horsetail include Equisetum fluviatile.

swamp horsetail (noun)	water horsetail (noun)
Eurasia; northern North America to Virginia	Eurasia; northern North America to Virginia